Archive for the ‘Tree Team and Propagation’ Category

An increasingly common sight around this time of year, Fraser fir is widely used as a Christmas tree. It is however included on the IUCN Red List of Threatened Plants as Endangered, as it’s threatened by an invasive insect in its native range in the Eastern United States.

There it grows with a number of other species that also grow in the Westonbirt collection such as the American mountain ash, Sorbus americana and mountain maple, Acer spicatum.

In U.K cultivation it is generally considered not to be particularly long lived.

Where can I find it?

A small but fine specimen grows close to Holford Ride in Victory Glade and other, younger plants can be found elsewhere in the Old Arboretum. You can locate specimens using the Westonbirt map, http://www.thewestonbirtmap.org.uk/

An important tree in the Westonbirt landscape, black pine is native to parts of Europe and is split into 5 subspecies, though it’s taxonomic treatment is somewhat controversial! We hope to add to our current specimens through collections we have made in south Italy.

Known as Calabrian pine to the locals, huge trees of what is generally known as Pinus nigra subsp. laricio grow in Aspromonte National Park and elsewhere.

Where can I find it?

Young and mature specimens can be found throughout the collection. You can locate specimens using the Westonbirt map, http://www.thewestonbirtmap.org.uk/

After an action packed 9 days in Calabria and Basilicata we have made a total of 45 collections from our target and associated species list. The pickings have been slightly mixed, with only herbarium material available in some cases, but our detailed collection records make all of this worthwhile.

Personal highlights for me so far include collecting seed of Oriental plane along a riverbed which was growing with alder and black poplar, among many other species. The fruits of the Oriental plane can be irritant so we had to handle them with care!

We have also been on the quest for Acer lobelii (Lobel’s maple), a somewhat little known maple endemic to southern Italy. So far, we have found it growing in two locations but, alas, no trees with seed. We do however have other areas in which it grows to explore.

Dan with Lobel’s maple

We’ve sent the first batch of seed to the UK already and we are now off to begin our collecting at Pollino National Park, where we hope to have good fortune with a number of maples, limes, oaks and pines.

New specimens are the lifeblood of any botanical collection. They are needed to provide an all-important uneven age structure, which should ultimately ensure there will be trees for future generations to enjoy.

Together with an expert from Royal Botanic Gardens Kew, we are about to set off on a three-week trip to Italy this autumn to search for internationally important tree species. We will be travelling light and covering as much ground as possible to make the most of this exciting opportunity. We’ll start collecting in the far southwest, before heading to the northeast.

Dendrologist Dan Crowley, Propagator Penny Jones and I will explore hundreds of miles of Italian countryside to seek out a target list of species that we have carefully selected for a variety of reasons. We will be accompanied throughout our trip by several Italian botanists and researchers, who have kindly helped us with the planning and logistics.

Left to right: Dan, Penny and Mark.

Some of the trees and shrubs identified as targets will be familiar, but it will be useful to test a more southerly provenance of these species in view of our predicted changing climate. When I asked Dan what he was hoping for, he immediately stated his main aim is to collect seed from Lobel’s maple (Acer lobelii), as this is rare in the wild and in cultivation. Penny wishes to see trees growing in their native range and habitat, which will importantly help us to position new plantings correctly within the Westonbirt landscape.

The species that are grand in size will be sought to maintain and develop the historic landscape at Westonbirt, but there is potential that some of these species could also have a big impact on the forestry industry in years to come. In partnership with Forest Research, we have been gathering information on a few key species which have the potential to become timber trees, hopefully with less risk of pest and disease.

Recent work by our Forest Research colleagues has shown that European silver fir (Abies alba) can be a productive species when grown in Britain, and could be more widely used to diversify our UK forests. The work showed that seed collected in Calabria, Italy performed well and we now need to establish better contacts in this area to collect new seed. We also want to learn more about how altitude, soils and other factors affect the growth of this tree.

We will endeavour to provide a few updates along the way, and as always, we look forward to seeing how well these new trees will grow at Westonbirt and elsewhere.

What is tree of the month?

Nyssa sylvatica

Why is it tree of the month?

One of the very best trees for autumn colour, Nyssa sylvatica never disappoints. It is somewhat overlooked at other points during the year but come October, it stands out even among the riot of colour with leaves that turn strong shades of red, orange and yellow. It really is worth trying to catch our trees at their best.

Native to eastern North America, it grows in the company of many other of our favourites for autumn colour including cherry birch, Betula lenta, bitternut, Carya cordiformis and red maple, Acer rubrum.

Where can I find it?

Examples can be found dotted around both the Old Arboretum and Silk Wood, including on Pool Avenue, Holford Ride and Broad Drive.

Once again our student arborist placement is well under way, and this year we’ve been thrilled to receive the generous support from two funders, the Finnis Scott Foundation and the Ernest Cook Trust, which has covered all the costs for one of our placements.

Joe is with us following his studies at Myerscough College, and having been with us for 2 months, he’s definitely getting stuck into the role. We asked him a few questions about his experience so far.

How’s the placement going so far?

It’s going well – there’s been a really good mix of practical activities and desk-based work. It’s been great as I’ve been able to really tailor the role in terms of getting bits of experience I need. For example, I wanted to get to grips with job-coding, which involves examining trees and determining their health and how much upkeep they need going forward. Mark [Westonbirt’s curator] has been really accommodating in making sure I’ve been able to take on tasks to ensure I gain skills in all areas of tree management. It’s also been good to be around people with so much knowledge. Everyone’s prepared to take the time out and pass on the benefits of their experience.

What’s been the best bit? What have you particularly enjoyed?

Definitely tractor driving, which I hadn’t done before I started at Westonbirt.

Is there one key thing you think you might take from this experience?

A highlight will definitely be being able to look back and see that I’ve been able to influence the landscape.

And what are your future plans?

I’m hoping to go into land management, working for a tree team as an arborist or I might even go freelance as a consultant.

Mark, who manages the placement and is Westonbirt Arboretum’s curator, believes fervently that this placement is of huge value both to the arboretum and the students.

“The placement is well established and has been running successfully for many years now, and it really benefits both parties.

The students obviously gain valuable work based experience and not only learn new skills but put existing experience into practice. They always enjoy the chance to use the academic knowledge gained at college or university in a ‘live’ situation, and take a lot back into the final year of study. They always find the chance to work alongside experienced practitioners very beneficial, as our arborists can pass on helpful insight and practical tips on a daily basis.

We in turn enjoy fresh faces in the team each year, bringing enthusiasm, the latest thinking and an exchange of ideas. It keeps us on our toes, as the students are constantly questioning our methods and reasoning. This regular scrutiny helps us to make sure we are on the right track with our plans and policies in particular.

The opportunities to gain essential experience can be limited, especially for mid-year students, and so we feel it is very important to keep this offer alive. After a year with us undertaking a wide variety of different tasks, students often have a much better idea as to which particular area they would like to specialise in the future too.”

Thanks again to the Finnis Scott Foundation and Ernest Cook Trust for their generous funding. Our student arborist placements run every year and need funding to cover a salary for the student, qualifications & certification, tools & equipment, learning visits to other arboreta, and clothing & personal protection equipment.

Over 450,000 visits are welcomed at Westonbirt each year and the vast majority of people enjoy a wonderful time in a picturesque setting. Thankfully, problems such as anti-social behaviour or vandalism are extremely rare indeed. And even more unusual is intentional damage to any of the trees and shrubs within our collection.

However, this was regrettably not the case recently. Our tree team found what strongly appears to be deliberate stripping of bark from the stem of an old Rhododendron, within a handsome group of specimens on Circular Drive. Sadly the damage didn’t stop there as not only was the bark been stripped from ground level to six feet up, but people’s names and other messages have been carved into the bare stem of this plant.

We are in the middle of a big project across the Old Arboretum of identifying Rhododendrons and this was one we were interested in as it produces an array of attractive white flowers tinged with pink every year. Unfortunately this Rhododendron group is also very special to someone, as it is commemorated.

Bark is to a woody plant what skin is to us humans; it performs the essential task of protecting the tissue within. The loss of this amount of bark has resulted in the need to fell the particular stem.

As Curator, it’s hard to understand the motivations for this and I’m sure it’s something that every botanical collection faces as their popularity and appeal grows far and wide.

Whilst I felt it was worth highlighting this as one of challenges we face here at Westonbirt, these incidents are particularly rare and the Rhododendron will, we hope, continue to live happily one stem down.

The Tree Team are currently working hard between Broad Drive and semi-natural woodland beyond the western side.

This is an area that has needed attention for quite some time as there is a line of young woodland trees, mainly ash and sycamore, that are adversely affecting the growth of our specimen trees.

This section is designated as ‘arboretum’ instead of ‘woodland’ within our long-standing Forest Design Plan, so we have decided to act now, in order to prevent further suppression of the specimen plants. The problem of suppression is exasperated on this particular side of Broad Drive by some over-mature Leyland cypress, that will at some point in the future be in danger of blowing over if left standing. They have become very big and tall, and unfortunately block out a great deal of important light.

So you may hear the sound of chainsaws, as the appearance of this part of Silk Wood changes for the better and this landscape restoration is complete. I can assure you that the views from Broad Drive will be much improved, and of course as always with any tree removal, we will be looking to plant a few more attractive specimens when the ground has had chance to settle down.

What is tree of the month?

Why is it tree of the month?

The evergreen magnolia from the south east United States is fairly often seen growing against walls in this part of the world but in slightly warmer climes it can make an impressive standalone tree.

There are many forms in cultivation with some noted for foliage but the real treat is the flowers. Appearing in late summer through early autumn, these can be over 20cm across and are creamy white and very nicely scented. Its tendency to flower somewhat intermittently means there is plenty of opportunity to have a good look.

Where can I find it?

Our best specimen grows against a wall of Keepers Cottage, adjacent to Propagation.